Screw-thread micrometer.



. L. C. BLOMSTROM.

SCREW THREAD MICHOMETER.

APPLICATION man 1AN.1.19|8.

1,300,692, Patented A911 15, 1919.

H mwN 'mm 2 LownLL c. BLoMsrnoM, or DETROIT, mcnreanj' SCREW-'runnen nicnoimrgm of Michigan, have `invented a new and useful' Screw-Thread Micrometer, of which the 'folf 1' lowing is a Specification.-

AThis invention relates to micrometer calipers especially adapted for gagin screw:

threads,v and'its object is'to provi e a micrometer caliper that may -be readily set to rotation is, applied to either, unless restraint' @any 'desired screw pitch idiamete'r without the necessity vof calculations vory consultation f that the intensity of frictional--engagenieiit ofl special tables, 'thus effecting 'af considerablefsaving of time as compared to 'instru-4 1 regulated, said collar is split,`and exterio'rly ments heretofore employed for alike purpose- Y In 'attaining this objwt the invention contemplates associating with-the'barreland@- spindleof a micrometer caliper two rela#- tively adjustable rotatable members, one carrying the usual vcircular scale, supplementing alinear scale on thebarrel, and the other being rigidly connected with the spindle, a helical scale being provided upon one of said members indicating various screw pitches for which the instrument is set by a proper ``nncrometer caliper when being set for a relative adjustment of the two members determined by referencefto lsaid helical scale, the two members bein rotated in unison corrcspondingly ,to the t imble of an ordinary givenl outside or point diameter 'of screw threads. f a

lThis object is attained by a construction which isillustrated in a preferred embodiment lby the accompanying drawings, wherein,

'Figure 1 is a View in side elevation of said preferred embodiment of the invention, the same being shown. engaged with the threads Fig.- 2 is an enlarged axial section, omitting the yoke portion, and Showing the engagement of the spindle with the barrel and withl specication bf Leiters referir.' fappneatipn mea January 7, 19118, seal im.' 210,627. I

i the threads of the spindle, 4land havinga -snu thimble 11 '\`vhich' has its rear end inwardly flanged v:isindicated 4at 12 -andrigidly enf gaged with the rear endof the spindle 3;'

' through,

[gleaned spindle screw-threaded E'into the bar-rel,

parts 1n ytheir. broadrel'ation being 'standard/5 in' micrometer calipers; f The bolt or serewf' 55 double-toothed anvilA 4 andthe tapered fend l extremity is formed with-a collar- 'engaging' go friction t therewith so that `said s leev'efan spindle l'w1ll tend lto -turnin unison when f is put uponone of said members@ In' order e5 between the collar 7 and spindle 3 'ma`y be tapered vand threaded to be engaged-by a blnding nut 8. At its frontend the sleeve 6:

' a linear scale 10 upon the barrel- -Therea'r -1 portion of the sleeve is engagedwithin a Within the thimble 11,:the sleeve 6 eXteriorly' f carries two helical scales 1 3 havingthe saine pitch as the threads of theI spindle, sight*v openings 4111 through which said scalemay be f read being providedjin the thimble 11; 'The 1 zero points of the scales 13' --and that oi the scale 9 are alined longit'ud inally' ofthel "f sleeve. 85 The raduations of -thescales 13 are'suchji as to indicate the various points'ftowhich the '-f sleeve 6 must be' rotatively and longitudi-jT nally adjusted relative to the thimble 11 and i the spindle 3 in order to relatively shift'said sleeve and thim'ble a distance equal to any". desired depth of thread, the indications of one of said scales being for'U. S, standard screw threads, and those of the other r i V-type threads, and the sight-openings being respectivelymarked U. S. and to disti'n-A guish between the scales readable there- In the use of thel above described instrufIA ment, there are two adjustments to be made if, as is usuall the case, thegivendata' in!l clude the pitc 'and outer diameter `oftlffe" screw to be gaged but n ot'jghet pitch diameter* in relatively rotating the sleeve 6 and thim ble 1l until a number on one of the scales 13 indicating the desired Pitchv is scales 9 and 1() exceeding the correspondingl spacing of the anvil-andispindle'by'adis-f' tance equaling exactl the single/depth 4o@ the desired thread. he other""adj1stment consists in rotating said sleeve and thimble in unison until thereading given byjthe scales 9 and 10 indicates the desired.,outer diameter for which a screw or bolt is to be gaged. {..It Willjbe evident that after majkin'g Ebotheof these adjustments the anvil andspindle will `be spaced adistance` equal tothe l reading given by. the, scales Y 9 andi() ,minus the reading through eitherof ithe windows; 14:,saidl distanceY beingthe xdesired pitch.'

diameter but calculation of said distance being rendered unnecessary. Which of the vtwo.adjustxnents is first madeis immaterial,

although it. maybe lsomewhat j more ,con-f' venient to first adjust the sleeve 6 andthimble 11- relatively. and subsequently adjust said .parts in unison.; f,

In using to gage a screw or bolt of known pitch di ameter, theY method followed might be. the same as for-,an ordinaryy micrometer caliper, the sleeve 4and. spindle being adjusted only -in;unis'onthe taken from the'scales 9 and101beinginsuch case that ofthe desired pitch diameter, f i;

Whatl claimis:

1v.; A. micrometer yoke, an: anvil and vbarrel respectively carried by said yoke, said barrel .having a scale extendinglongitudinally thereon, a spindlel adjustable. in said barrel to or from the anvil, a sleeve 'embracing said barrel and carryinga scale readingvin screw pitches, and a thimble rigidly engaged Withfsaid Spindle andemlbracing said sleeve, the sleeve and thimble being relatively longitudinally adjustable to set the latter With reference to a thimble rigidly engagedvvithsaid spindle and embracing said sleeve, the thimble being adapted to be Iset with reference to the scale on the sleeve through relative rotation of the sleeve and spindle, and the sleeve be registered with the corresponding openi :14, This 'j has the eii'ect of giving a rea ing on the the above described. instrument caliper j comprising a by said yoke, said barrel h'aving a scale ing adapted to be set with relation to the scale on the barrel through adjustment thereof inunison with the spindle,

A micrometer elgipeir' comprising a yoke, an anvil'and barrel'respectivelycarried by said yoke, barrel having a scale extending longitudinally thereon, a spindle adj.ust'able.in,.said barrel to or from the anvil, a sleeveembracing said barrel and carrying, a helical scale reading lin screw pitches, said sleeve and spindle having en-f gaged screw-,threaded portions, the pitch of which is also that of said helical scale, and a thimble rigidly engaged with saidspindle and embracingsaid sleeve andvformed with a sigh-tfwindow with which the indicia of the helical scalemayfbe respectively. registered through. relativeroftation of the sleeve 'and spindle, the sleeve-beingadapted to-be set with reference to the scale on the barrel by adjustmentof ythe sleeve in unison with the spindle.

v4. A crometerff caliper comprisingA a yoke, an anvil and .barrel respectivelyvcarried by said yoke',l said barrel having a scale extending. longitudinally thereon, a vspindle screw-threaded v`in.r said barrel for adjustment by rotationl tol or from .the anvil, la sleeve embracing saidbarrel and carrying a scale reading in screw-pitches, and a thimble rigidlygengaged: with said spindleand embracing said sleeve, the sleeve andthimbleiV being relativelyflongitudinally adj ustable toV set .the .flatter with reference ,'to the scale on the .former andbeingfadjustable in unison with the spindlefand With-reference to the scale on the Ibar-rel to set Ythesp-indle with relationto theanvil. v

5.' A micrometercaliper comprising -aA yoke, an anvil and :barrel respectively carried by said yoke, said barrel having a scale I extending longitudinally thereon, a spindle screw-threaded in. said barrel for adjustment by rotationto or from the anvil, a sleeve embracing" said barrel and carrying a scale supplementingthescale onthe barrel and further carrying a helical scale reading. in. screw .pitches,'the zero points "of 'said scales'beingin alinement, said sleeve and. spindle having engaged screw-threaded portions, the pitch of which is also th'at of said' helical scale, and. athimble rigidly engaged with said spindle and embracing said sleeve,

the thimble being adjustedto be set with reference to the helical scale on the sleeve through relative rotation of sleeve and spindle, and the` sleeve being adapted to beset with relation to the i,scale on the barrelA throughadjustment thereof in-unison with I the spindle.` H r j.

6. A. 'micrometercaliper. comprising a l yoke, an anvil' and barrel respectively car ried by sai-d yoke, said barrel having a scale extendin longitudinally. thereon, a spindle adjustah e in said barrel-fte or4 from the anvil, two members comprising a sleeve embracing said barrel and a thimble rigidly engaged with said spindle and embracing said sleeve, one of said members having a sea-1e thereon reading in screw pitches, said members being relatively adjustable longitudinally to set one With reference to the and With reference to the Scale on the barrel 10 to set the spindle with relation to the anYil.

In testimony whereof I sign this Speelfication.

LOWELL C. BLOMSTROM.

Gopiel of this patent my be obtained for ive cents each, by addressing the Commissioner of Patents, Washington, D. C." 

